The order in which you carry out energy improvements matters as much as which ones you choose. Insulation before a heat pump increases the system’s efficiency and is a condition of the Boiler Upgrade Scheme grant. Solar panels before battery storage means the battery has generation to store. Even without those dependencies, the financial return per pound spent varies significantly between measures: loft insulation typically returns more per pound than any other single improvement, while solid wall insulation and double glazing have payback periods that often stretch beyond the loan term. Getting the sequence right means spending less to achieve the same outcome.
This sequencer takes your property profile and produces a recommended sequence of improvements in order of financial return, with dependency rules applied automatically. Each step shows the illustrative cost range, annual saving, payback period, grant availability, and the reason it sits where it does in the sequence. All figures are illustrative estimates. Actual costs and savings depend on your specific property, installer, and tariff. The JavaScript for this tool is loaded via WPCode.
At a Glance
- Insulation measures almost always come first. Loft insulation has the highest financial return per pound of any common energy improvement and takes as little as one to four years to pay back. Cavity wall insulation is close behind. Both must be completed before a heat pump installation qualifies for the Boiler Upgrade Scheme grant.
- The heat pump’s position in the sequence depends on your current fuel. For oil and LPG properties, the heat pump produces a meaningful annual saving and typically sits third or fourth in the sequence after insulation. For gas properties, the running cost saving is marginal at current tariffs and the heat pump sits lower unless the BUS grant justifies the capital outlay.
- Solar panels and battery storage are independent of the heating sequence. They can be installed at any stage, though battery storage is only financially justified once solar panels are generating electricity to store.
- Your construction era determines which wall insulation type applies. Pre-1920 properties typically have solid walls and require external or internal wall insulation. Post-1920s properties typically have cavity walls and require cavity fill. Specifying the wrong type produces incorrect cost and saving estimates.
- Budget constraints are applied to show which measures fit your available spend. Measures beyond your budget are shown separately so you can plan future phases.
Home energy upgrade sequencer
Enter your property profile to see a recommended sequence of improvements in order of financial return. All figures are illustrative estimates.
Your property
Already completed (tick all that apply)
Available budget
How This Sequencer Works
Applicability rules
Which measures appear for your property
Not all measures apply to all properties. Loft insulation only applies to houses and top-floor flats. Solid wall insulation applies to pre-1920 properties with no cavity. Cavity wall insulation applies to post-1920s properties with cavity walls. Heat pumps require outdoor space and are not included for mid-floor flats. Solar panels require roof access and are not included for ground and mid-floor flats. Measures that do not apply to your property type and era are excluded from the sequence and listed separately.
Sequencing logic
How the order is determined
Within dependency constraints, measures are ordered by financial return per pound spent: the annual saving divided by the installed cost. Loft insulation consistently ranks first because the cost is low and the saving is immediate. Dependency rules then override pure ROI ordering where needed: applicable insulation measures are always sequenced before a heat pump, because improving insulation raises the heat pump’s efficiency and clearing outstanding EPC insulation recommendations is required for the Boiler Upgrade Scheme grant. Battery storage is removed from the sequence if solar panels have not been installed.
Budget filter
How the budget affects the sequence
The budget filter uses the midpoint of each measure’s illustrative cost range. Measures within your budget are shown in full. Measures beyond it are shown at reduced opacity and labelled as outside budget, so you can see the full recommended sequence for future planning while identifying which steps are achievable in the current phase. The cumulative summary reflects only the within-budget measures.
Limitations
What the sequencer does not account for
Cost and saving figures are illustrative UK averages and do not reflect your specific property size, local installer rates, or current energy tariff. The sequencer uses a single wall insulation type per era rather than surveying the actual construction. Some properties built in the 1920s to 1960s period have solid walls rather than cavity walls, and some post-1960s properties already have adequate insulation. A professional energy assessment before committing to any sequence is the most accurate way to confirm which measures are applicable and what savings they are likely to achieve.
Understanding the Dependency Rules
Three dependency rules are applied automatically in the sequencer. Understanding them helps explain why a measure you might expect to see earlier appears later in the sequence, or why a measure is excluded entirely.
The first and most important rule is insulation before heat pump. A heat pump’s seasonal efficiency (SCOP) is directly determined by how warm the circulating water needs to be to maintain comfortable temperatures. In a poorly insulated property, higher flow temperatures are required, which reduces the SCOP and increases running costs. Improving insulation first allows the heat pump to be specified at a lower flow temperature and smaller system size, both of which reduce capital and running costs. Beyond the efficiency argument, the Boiler Upgrade Scheme requires a valid EPC with no outstanding recommendations for loft or cavity wall insulation before a grant can be claimed. This makes the dependency a practical requirement, not merely a recommendation. The second rule is solar before battery. Battery storage has no financial return without solar generation to store. A battery installation before solar panels is excluded from the sequence entirely, though it appears in the unavailable section so you can see it as a future option once solar is installed. The third rule is that measures already marked as completed are removed from the sequence but their EPC improvement is counted toward the current starting position.
How to Use This Sequencer
Select your property type and era
Choose the option that best describes your property. For the construction era, pre-1920 covers Victorian and Edwardian properties, 1920s to 1960s covers interwar and early postwar, and post-1960s covers later builds. If you are unsure of the era, a rough guide is: pre-1920 properties typically have bay windows and high ceilings; 1920s to 1960s properties are typically semi-detached or terraced with lower ceilings; post-1960s properties include most estates built from the 1970s onwards.
Set your EPC rating and fuel type
Find your current EPC on the government’s Find an Energy Certificate service if you do not have a paper copy. The EPC rating determines which measures are most urgently needed and affects the heat pump saving calculation. The fuel type determines whether a heat pump produces a running cost saving: for oil and LPG properties the saving is typically meaningful; for gas properties it is marginal at current tariffs.
Tick what you have already done
Tick any measures already completed. These are removed from the recommended sequence. If insulation is already done, the heat pump dependency condition is treated as met and the heat pump can appear earlier in the sequence. If solar panels are already installed, battery storage becomes available and appears in the sequence.
Set your available budget
Select the budget range that reflects what you are considering spending now, not the total across all future phases. Measures within budget are shown in full. Those beyond budget are shown at reduced opacity. You can change the budget to plan future phases. The sequence order does not change with budget: the recommended sequence is always shown in full so you can see what comes next when your budget allows.
Related Tools and Guides
Tool
Boiler vs heat pump: year-by-year cost comparison
Once the sequencer shows the heat pump as a recommended step, use this calculator to model the fifteen-year cost comparison between replacing your boiler and installing a heat pump, including energy price scenarios.
Tool
Solar panel savings calculator
Once solar panels appear in your sequence, use this calculator to estimate annual generation, bill saving, and export income based on your specific roof orientation, shading, and self-consumption rate.
Tool
Energy efficiency loan payback calculator
Model when cumulative energy savings overtake total loan interest for any measure in the sequence. Use with the cost and saving figures from the sequencer to assess the loan position for each step.
Guide
Government grants vs home improvement loans
Covers the Boiler Upgrade Scheme, ECO4, and the Great British Insulation Scheme in full: eligibility conditions, how grants are claimed, and how to combine grant funding with a loan for the balance.
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Checking won’t harm your credit scoreFrequently Asked Questions
My property was built in the 1930s but I think it has solid walls. Which era should I select?
The sequencer uses construction era as a proxy for wall type, with 1920s to 1960s mapped to cavity wall insulation and pre-1920s mapped to solid wall insulation. This is a simplification: a minority of interwar properties were built with solid walls rather than cavity construction, and the only reliable way to determine which applies to your property is to have it checked by a surveyor or energy assessor. If you are unsure, select pre-1920s in the sequencer to see the solid wall insulation option, then separately check which applies before commissioning any work.
You can also look for physical clues: a solid wall is typically around 22 centimetres thick (measure at a window reveal or door frame), while a cavity wall is usually 28 to 32 centimetres. Brick bond pattern can also indicate construction type in some cases. If wall insulation is a priority and you are uncertain of the type, a professional energy assessment will confirm the construction and give a site-specific saving estimate, which will be more accurate than the illustrative figures in this tool.
The sequencer recommends insulation before a heat pump, but I need the heat pump urgently. Can I do it in a different order?
Yes, the sequence is a recommendation based on financial efficiency, not a requirement. You can install a heat pump before completing insulation improvements. The consequences are that the heat pump will operate at lower efficiency than it would in a better-insulated property, because it needs to run at higher flow temperatures. This means higher running costs and a longer payback period. The system may also be specified at a larger size than a post-insulation installation would require, which increases the capital cost.
There is also a grant implication. The Boiler Upgrade Scheme requires a valid EPC with no outstanding recommendations for loft or cavity wall insulation before an application can be made. If your property has outstanding insulation recommendations on its EPC, the BUS grant is not available until those recommendations are cleared, either by completing the works or by having a new EPC assessed after the works are done. If the £7,500 grant is a significant factor in the financial case for the heat pump, completing the insulation first to clear the EPC recommendations is the practical prerequisite rather than just a sequencing preference.
Why is double glazing so low in the sequence?
Double glazing has a low financial return per pound spent compared with insulation measures. The typical cost of replacing single-glazed windows with double glazing in a house is £3,000 to £8,000, while the annual energy saving is only £100 to £250 per year. That gives a simple payback period of twelve to forty years on the energy saving alone, which is among the longest of any common energy improvement. The improvement in comfort, noise reduction, and security has real value, but those benefits do not appear in a financial return calculation.
For properties that already have double glazing, upgrading to triple glazing produces an even lower financial return and is rarely justified on energy saving grounds alone. The sequencer reflects the honest financial position: double glazing typically comes late in the sequence because the same money spent on loft insulation or a heat pump produces a significantly larger financial return. This does not mean glazing improvements are not worthwhile: it means they are better funded from discretionary budget after higher-return measures are completed, rather than as the first step in an energy improvement programme.
How do I fund multiple measures across different phases?
Several approaches work depending on the amounts involved and the timing between phases. For insulation measures in the first phase, amounts are typically small enough for an unsecured personal loan or, where grant funding applies, the grant may cover the full cost. For a heat pump in a later phase, the BUS grant covers £7,500 and an unsecured or secured loan covers the balance. For solar panels, no grant is available and a loan typically covers the full cost, with the saving from the previous measures having reduced the overall energy bill by the time solar is installed.
Some homeowners prefer to fund all planned phases in a single secured loan when the total budget is above around £15,000 to £20,000, as the lower rate on a secured product reduces total interest compared with multiple smaller unsecured loans taken at different times. The trade-off is that securing the loan against the property at the first phase means the full loan is outstanding while only the first phase improvement is generating a saving. Our guide to home improvement loans for energy efficiency upgrades covers the loan type decision for phased improvement programmes, and the secured vs unsecured threshold tool helps identify at which loan size the secured route becomes cost-effective.
Squaring Up
The order of energy improvements matters because the measures interact: insulation makes a heat pump more efficient and unlocks the BUS grant, solar makes battery storage financially viable, and doing the highest-return measures first means the money you spend on later phases is partly funded by the savings from earlier ones. A sequencer built around financial return per pound, with dependency rules applied, gives a more useful answer than a generic priority list.
The figures in this tool are illustrative and the sequence is a starting point rather than a final specification. A professional energy assessment before committing to any phase will give property-specific costs, savings, and EPC projections that are more accurate than any UK-average estimate can provide. Use the sequencer to understand the logic and plan the phases, then verify the detail before spending.
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Checking won’t harm your credit score Check eligibilityThis tool is for illustrative purposes only and does not constitute financial or energy advice. All cost and saving figures are illustrative UK averages and will differ from actual outcomes, which depend on your specific property, installer, location, and energy tariff. Grant eligibility conditions and availability are subject to change: verify current status on GOV.UK before making any decisions based on grant funding. A professional energy assessment is recommended before committing to any improvement programme. Your home may be at risk if you do not keep up repayments on a secured loan.
